drivers/rtc/rtc-mt6397.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3 * Copyright (c) 2014-2015 MediaTek Inc.
   4 * Author: Tianping.Fang <tianping.fang@mediatek.com>
   5 */
   6
   7 #include <linux/err.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/mfd/mt6397/core.h>
  10 #include <linux/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regmap.h>
  14 #include <linux/rtc.h>
  15 #include <linux/mfd/mt6397/rtc.h>
  16 #include <linux/mod_devicetable.h>
  17
  18 static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
  19 {
  20         int ret;
  21         u32 data;
  22
  23         ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_WRTGR, 1);
  24         if (ret < 0)
  25                 return ret;
  26
  27         ret = regmap_read_poll_timeout(rtc->regmap,
  28                                         rtc->addr_base + RTC_BBPU, data,
  29                                         !(data & RTC_BBPU_CBUSY),
  30                                         MTK_RTC_POLL_DELAY_US,
  31                                         MTK_RTC_POLL_TIMEOUT);
  32         if (ret < 0)
  33                 dev_err(rtc->dev, "failed to write WRTGE: %d\n", ret);
  34
  35         return ret;
  36 }
  37
  38 static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
  39 {
  40         struct mt6397_rtc *rtc = data;
  41         u32 irqsta, irqen;
  42         int ret;
  43
  44         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
  45         if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
  46                 rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
  47                 irqen = irqsta & ~RTC_IRQ_EN_AL;
  48                 mutex_lock(&rtc->lock);
  49                 if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
  50                                  irqen) < 0)
  51                         mtk_rtc_write_trigger(rtc);
  52                 mutex_unlock(&rtc->lock);
  53
  54                 return IRQ_HANDLED;
  55         }
  56
  57         return IRQ_NONE;
  58 }
  59
  60 static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
  61                                struct rtc_time *tm, int *sec)
  62 {
  63         int ret;
  64         u16 data[RTC_OFFSET_COUNT];
  65
  66         mutex_lock(&rtc->lock);
  67         ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
  68                                data, RTC_OFFSET_COUNT);
  69         if (ret < 0)
  70                 goto exit;
  71
  72         tm->tm_sec = data[RTC_OFFSET_SEC];
  73         tm->tm_min = data[RTC_OFFSET_MIN];
  74         tm->tm_hour = data[RTC_OFFSET_HOUR];
  75         tm->tm_mday = data[RTC_OFFSET_DOM];
  76         tm->tm_mon = data[RTC_OFFSET_MTH];
  77         tm->tm_year = data[RTC_OFFSET_YEAR];
  78
  79         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
  80 exit:
  81         mutex_unlock(&rtc->lock);
  82         return ret;
  83 }
  84
  85 static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
  86 {
  87         time64_t time;
  88         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
  89         int days, sec, ret;
  90
  91         do {
  92                 ret = __mtk_rtc_read_time(rtc, tm, &sec);
  93                 if (ret < 0)
  94                         goto exit;
  95         } while (sec < tm->tm_sec);
  96
  97         /* HW register use 7 bits to store year data, minus
  98          * RTC_MIN_YEAR_OFFSET before write year data to register, and plus
  99          * RTC_MIN_YEAR_OFFSET back after read year from register
 100          */
 101         tm->tm_year += RTC_MIN_YEAR_OFFSET;
 102
 103         /* HW register start mon from one, but tm_mon start from zero. */
 104         tm->tm_mon--;
 105         time = rtc_tm_to_time64(tm);
 106
 107         /* rtc_tm_to_time64 covert Gregorian date to seconds since
 108          * 01-01-1970 00:00:00, and this date is Thursday.
 109          */
 110         days = div_s64(time, 86400);
 111         tm->tm_wday = (days + 4) % 7;
 112
 113 exit:
 114         return ret;
 115 }
 116
 117 static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
 118 {
 119         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 120         int ret;
 121         u16 data[RTC_OFFSET_COUNT];
 122
 123         tm->tm_year -= RTC_MIN_YEAR_OFFSET;
 124         tm->tm_mon++;
 125
 126         data[RTC_OFFSET_SEC] = tm->tm_sec;
 127         data[RTC_OFFSET_MIN] = tm->tm_min;
 128         data[RTC_OFFSET_HOUR] = tm->tm_hour;
 129         data[RTC_OFFSET_DOM] = tm->tm_mday;
 130         data[RTC_OFFSET_MTH] = tm->tm_mon;
 131         data[RTC_OFFSET_YEAR] = tm->tm_year;
 132
 133         mutex_lock(&rtc->lock);
 134         ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
 135                                 data, RTC_OFFSET_COUNT);
 136         if (ret < 0)
 137                 goto exit;
 138
 139         /* Time register write to hardware after call trigger function */
 140         ret = mtk_rtc_write_trigger(rtc);
 141
 142 exit:
 143         mutex_unlock(&rtc->lock);
 144         return ret;
 145 }
 146
 147 static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 148 {
 149         struct rtc_time *tm = &alm->time;
 150         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 151         u32 irqen, pdn2;
 152         int ret;
 153         u16 data[RTC_OFFSET_COUNT];
 154
 155         mutex_lock(&rtc->lock);
 156         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
 157         if (ret < 0)
 158                 goto err_exit;
 159         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
 160         if (ret < 0)
 161                 goto err_exit;
 162
 163         ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
 164                                data, RTC_OFFSET_COUNT);
 165         if (ret < 0)
 166                 goto err_exit;
 167
 168         alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
 169         alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
 170         mutex_unlock(&rtc->lock);
 171
 172         tm->tm_sec = data[RTC_OFFSET_SEC];
 173         tm->tm_min = data[RTC_OFFSET_MIN];
 174         tm->tm_hour = data[RTC_OFFSET_HOUR];
 175         tm->tm_mday = data[RTC_OFFSET_DOM];
 176         tm->tm_mon = data[RTC_OFFSET_MTH];
 177         tm->tm_year = data[RTC_OFFSET_YEAR];
 178
 179         tm->tm_year += RTC_MIN_YEAR_OFFSET;
 180         tm->tm_mon--;
 181
 182         return 0;
 183 err_exit:
 184         mutex_unlock(&rtc->lock);
 185         return ret;
 186 }
 187
 188 static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 189 {
 190         struct rtc_time *tm = &alm->time;
 191         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 192         int ret;
 193         u16 data[RTC_OFFSET_COUNT];
 194
 195         tm->tm_year -= RTC_MIN_YEAR_OFFSET;
 196         tm->tm_mon++;
 197
 198         data[RTC_OFFSET_SEC] = tm->tm_sec;
 199         data[RTC_OFFSET_MIN] = tm->tm_min;
 200         data[RTC_OFFSET_HOUR] = tm->tm_hour;
 201         data[RTC_OFFSET_DOM] = tm->tm_mday;
 202         data[RTC_OFFSET_MTH] = tm->tm_mon;
 203         data[RTC_OFFSET_YEAR] = tm->tm_year;
 204
 205         mutex_lock(&rtc->lock);
 206         if (alm->enabled) {
 207                 ret = regmap_bulk_write(rtc->regmap,
 208                                         rtc->addr_base + RTC_AL_SEC,
 209                                         data, RTC_OFFSET_COUNT);
 210                 if (ret < 0)
 211                         goto exit;
 212                 ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
 213                                    RTC_AL_MASK_DOW);
 214                 if (ret < 0)
 215                         goto exit;
 216                 ret = regmap_update_bits(rtc->regmap,
 217                                          rtc->addr_base + RTC_IRQ_EN,
 218                                          RTC_IRQ_EN_ONESHOT_AL,
 219                                          RTC_IRQ_EN_ONESHOT_AL);
 220                 if (ret < 0)
 221                         goto exit;
 222         } else {
 223                 ret = regmap_update_bits(rtc->regmap,
 224                                          rtc->addr_base + RTC_IRQ_EN,
 225                                          RTC_IRQ_EN_ONESHOT_AL, 0);
 226                 if (ret < 0)
 227                         goto exit;
 228         }
 229
 230         /* All alarm time register write to hardware after calling
 231          * mtk_rtc_write_trigger. This can avoid race condition if alarm
 232          * occur happen during writing alarm time register.
 233          */
 234         ret = mtk_rtc_write_trigger(rtc);
 235 exit:
 236         mutex_unlock(&rtc->lock);
 237         return ret;
 238 }
 239
 240 static const struct rtc_class_ops mtk_rtc_ops = {
 241         .read_time  = mtk_rtc_read_time,
 242         .set_time   = mtk_rtc_set_time,
 243         .read_alarm = mtk_rtc_read_alarm,
 244         .set_alarm  = mtk_rtc_set_alarm,
 245 };
 246
 247 static int mtk_rtc_probe(struct platform_device *pdev)
 248 {
 249         struct resource *res;
 250         struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
 251         struct mt6397_rtc *rtc;
 252         int ret;
 253
 254         rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
 255         if (!rtc)
 256                 return -ENOMEM;
 257
 258         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 259         rtc->addr_base = res->start;
 260
 261         rtc->irq = platform_get_irq(pdev, 0);
 262         if (rtc->irq < 0)
 263                 return rtc->irq;
 264
 265         rtc->regmap = mt6397_chip->regmap;
 266         mutex_init(&rtc->lock);
 267
 268         platform_set_drvdata(pdev, rtc);
 269
 270         rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
 271         if (IS_ERR(rtc->rtc_dev))
 272                 return PTR_ERR(rtc->rtc_dev);
 273
 274         ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
 275                                         mtk_rtc_irq_handler_thread,
 276                                         IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
 277                                         "mt6397-rtc", rtc);
 278
 279         if (ret) {
 280                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
 281                         rtc->irq, ret);
 282                 return ret;
 283         }
 284
 285         device_init_wakeup(&pdev->dev, 1);
 286
 287         rtc->rtc_dev->ops = &mtk_rtc_ops;
 288
 289         ret = rtc_register_device(rtc->rtc_dev);
 290         if (ret)
 291                 goto out_free_irq;
 292
 293         return 0;
 294
 295 out_free_irq:
 296         free_irq(rtc->irq, rtc);
 297         return ret;
 298 }
 299
 300 #ifdef CONFIG_PM_SLEEP
 301 static int mt6397_rtc_suspend(struct device *dev)
 302 {
 303         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 304
 305         if (device_may_wakeup(dev))
 306                 enable_irq_wake(rtc->irq);
 307
 308         return 0;
 309 }
 310
 311 static int mt6397_rtc_resume(struct device *dev)
 312 {
 313         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 314
 315         if (device_may_wakeup(dev))
 316                 disable_irq_wake(rtc->irq);
 317
 318         return 0;
 319 }
 320 #endif
 321
 322 static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
 323                         mt6397_rtc_resume);
 324
 325 static const struct of_device_id mt6397_rtc_of_match[] = {
 326         { .compatible = "mediatek,mt6323-rtc", },
 327         { .compatible = "mediatek,mt6397-rtc", },
 328         { }
 329 };
 330 MODULE_DEVICE_TABLE(of, mt6397_rtc_of_match);
 331
 332 static struct platform_driver mtk_rtc_driver = {
 333         .driver = {
 334                 .name = "mt6397-rtc",
 335                 .of_match_table = mt6397_rtc_of_match,
 336                 .pm = &mt6397_pm_ops,
 337         },
 338         .probe  = mtk_rtc_probe,
 339 };
 340
 341 module_platform_driver(mtk_rtc_driver);
 342
 343 MODULE_LICENSE("GPL v2");
 344 MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
 345 MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");